From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/video/fbdev/bt455.h | 90 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/video/fbdev/bt455.h (limited to 'drivers/video/fbdev/bt455.h') diff --git a/drivers/video/fbdev/bt455.h b/drivers/video/fbdev/bt455.h new file mode 100644 index 000000000..dd1404b40 --- /dev/null +++ b/drivers/video/fbdev/bt455.h @@ -0,0 +1,90 @@ +/* + * linux/drivers/video/bt455.h + * + * Copyright 2003 Thiemo Seufer + * Copyright 2016 Maciej W. Rozycki + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + */ +#include + +/* + * Bt455 byte-wide registers, 32-bit aligned. + */ +struct bt455_regs { + volatile u8 addr_cmap; + u8 pad0[3]; + volatile u8 addr_cmap_data; + u8 pad1[3]; + volatile u8 addr_clr; + u8 pad2[3]; + volatile u8 addr_ovly; + u8 pad3[3]; +}; + +static inline void bt455_select_reg(struct bt455_regs *regs, int ir) +{ + mb(); + regs->addr_cmap = ir & 0x0f; +} + +static inline void bt455_reset_reg(struct bt455_regs *regs) +{ + mb(); + regs->addr_clr = 0; +} + +/* + * Read/write to a Bt455 color map register. + */ +static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey) +{ + mb(); + regs->addr_cmap_data; + rmb(); + *grey = regs->addr_cmap_data & 0xf; + rmb(); + regs->addr_cmap_data; +} + +static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_cmap_data = 0x0; + wmb(); + regs->addr_cmap_data = grey & 0xf; + wmb(); + regs->addr_cmap_data = 0x0; +} + +static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey) +{ + wmb(); + regs->addr_ovly = 0x0; + wmb(); + regs->addr_ovly = grey & 0xf; + wmb(); + regs->addr_ovly = 0x0; +} + +static inline void bt455_read_cmap_entry(struct bt455_regs *regs, + int cr, u8 *grey) +{ + bt455_select_reg(regs, cr); + bt455_read_cmap_next(regs, grey); +} + +static inline void bt455_write_cmap_entry(struct bt455_regs *regs, + int cr, u8 grey) +{ + bt455_select_reg(regs, cr); + bt455_write_cmap_next(regs, grey); +} + +static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey) +{ + bt455_reset_reg(regs); + bt455_write_ovly_next(regs, grey); +} -- cgit v1.3.1